Validity and Reliability of Four Parent/Patient-Reported Outcome Measures for Juvenile Idiopathic Arthritis Remote Monitoring.

OBJECTIVE: The aim of this work was to provide evidence of validity and reliability for 4 parent/child-reported outcome measures included in the Outcome Measures in Rheumatology juvenile idiopathic arthritis core domain set: the evaluation of the child's pain and level of disease activity, the assessment of morning stiffness duration, and an active joint count for proxy/self-assessment. METHODS: Patients were included in the multinational study Epidemiology Treatment and Outcome of Childhood Arthritis. Criterion validity was assessed by examining the correlation of the 4 tested measures with physician measures and the clinical Juvenile Arthritis Disease Activity Score in 10 joints (cJADAS10) in the whole sample and after grouping patients by International League of Associations for Rheumatology (ILAR) category, geographic area, and education level. Reliability was assessed comparing 2 visits 7-14 days apart with intraclass correlation coefficients (ICCs). RESULTS: A total of 8,643 parents and 6,060 patients had all the evaluations available. Correlations of tested measures were moderate (0.4-0.7) with physician-reported measures. The level of correlation with the cJADAS10 remained stable after grouping patients by ILAR category, geographic areas, and level of education of the parent filling the questionnaire. In 442 parents and 344 children, ICCs ranged between 0.79 and 0.87 for parents and 0.81 and 0.88 for children. CONCLUSION: The 4 tested parent/child-reported outcomes showed good criterion validity and excellent reliability. These tools can be considered for remote patient assessment, when in-person evaluation might not be possible.

Fused Omics Data Models Reveal Gut Microbiome Signatures Specific of Inactive Stage of Juvenile Idiopathic Arthritis in Pediatric Patients.

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in children. Herein, we evaluated the relationship between the gut microbiome (GM) and disease phenotype by an integrated omics fused approach. In a multicenter, observational cohort study, stools from Italian JIA patients were collected at baseline, active, and inactive disease stages, and their GM compared to healthy controls (CTRLs). The microbiota metabolome was analyzed to detect volatile- and non-volatile organic compounds (VOCs); the data were fused with operational taxonomic units (OTUs) from 16S RNA targeted-metagenomics and classified by chemometric models. Non-VOCs did not characterize JIA patients nor JIA activity stages compared to CTRLs. The core of VOCs, (Ethanol, Methyl-isobutyl-ketone, 2,6-Dimethyl-4-heptanone and Phenol) characterized patients at baseline and inactive disease stages, while the OTUs represented by Ruminococcaceae, Lachnospiraceae and Clostridiacea discriminated between JIA inactive stage and CTRLs. No differences were highlighted amongst JIA activity stages. Finally, the fused data discriminated inactive and baseline stages versus CTRLs, based on the contribution of the invariant core of VOCs while Ruminococcaceae concurred for the inactive stage versus CTRLs comparison. In conclusion, the GM signatures enabled to distinguish the inactive disease stage from CTRLs.

MTX intolerance in children and adolescents with juvenile idiopathic arthritis.

MTX is the medication most commonly used for antirheumatic treatment in juvenile idiopathic arthritis. It has high efficacy, is usually well tolerated and has an excellent safety profile. However, frequently intolerance symptoms develop that manifest as nausea, feelings of disgust or abdominal complaints prior to or directly after administration of the medication. No obvious toxicity is causing these intolerance symptoms, but symptoms are strictly limited to MTX and not transferred to other medications. MTX intolerance causes a significant reduction of quality of life in affected patients, frequently puts the treating physician in difficult situations regarding treatment choice, and may lead to uncomfortable decisions whether or not to stop an otherwise effective drug. Conventional countermeasures such as antiemetics, change of route from subcutaneous to oral or vice versa, or taste masking usually have only a limited effect. In this review, we present the current knowledge on MTX intolerance, its clinical picture and commonly employed strategies. We also consider newer behavioural treatment strategies that may offer a more effective symptom control.

Treatment to Target Using Recombinant Interleukin-1 Receptor Antagonist as First-Line Monotherapy in New-Onset Systemic Juvenile Idiopathic Arthritis: Results From a Five-Year Follow-Up Study.

OBJECTIVE: Systemic juvenile idiopathic arthritis (JIA) is a multifactorial autoinflammatory disease with a historically poor prognosis. With current treatment regimens, approximately half of patients still experience active disease after 1 year of therapy. This study was undertaken to evaluate a treat-to-target approach using recombinant interleukin-1 receptor antagonist (rIL-1Ra; anakinra) as first-line monotherapy to achieve early inactive disease and prevent damage. METHODS: In this single-center, prospective study, patients with new-onset systemic JIA with an unsatisfactory response to nonsteroidal antiinflammatory drugs received rIL-1Ra monotherapy according to a treat-to-target strategy. Patients with an incomplete response to 2 mg/kg rIL-1Ra subsequently received 4 mg/kg rIL-1Ra or additional prednisolone, or switched to alternative therapy. For patients in whom inactive disease was achieved, rIL-1Ra was tapered after 3 months and subsequently stopped. RESULTS: Forty-two patients, including 12 who had no arthritis at disease onset, were followed up for a median of 5.8 years. The median time to achieve inactive disease was 33 days. At 1 year, 76% had inactive disease, and 52% had inactive disease while not receiving medication. High neutrophil counts at baseline and a complete response after 1 month of rIL-1Ra were highly associated with inactive disease at 1 year. After 5 years of follow-up, 96% of the patients included had inactive disease, and 75% had inactive disease while not receiving medication. Articular or extraarticular damage was reported in <5%, and only 33% of the patients received glucocorticoids. Treatment with rIL-1Ra was equally effective in systemic JIA patients without arthritis at disease onset. CONCLUSION: Treatment to target, starting with first-line, short-course monotherapy with rIL-1Ra, is a highly efficacious strategy to induce and sustain inactive disease and to prevent disease- and glucocorticoid-related damage in systemic JIA.

Microbiome Analytics of the Gut Microbiota in Patients With Juvenile Idiopathic Arthritis: A Longitudinal Observational Cohort Study.

OBJECTIVE: To assess the composition of gut microbiota in Italian and Dutch patients with juvenile idiopathic arthritis (JIA) at baseline, with inactive disease, and with persistent activity compared to healthy controls. METHODS: In a multicenter, prospective, observational cohort study, fecal samples were collected at baseline from 78 Italian and 21 Dutch treatment-naive JIA patients with <6 months of disease duration and compared to 107 geographically matched samples from healthy children. Forty-four follow-up samples from patients with inactive disease and 25 follow-up samples from patients with persistent activity were analyzed. Gut microbiota composition was determined by 16S ribosomal RNA-based metagenomics. Alpha- and ß-diversity were computed, and log ratios of relative abundance were compared between patients and healthy controls using random forest models and logistic regression. RESULTS: Baseline samples from Italian patients showed reduced richness compared to healthy controls (P < 0.001). Random forest models distinguished between Italian patient baseline samples and healthy controls and suggested differences between Dutch patient samples and healthy controls (areas under the curve >0.99 and 0.71, respectively). The operational taxonomic units (OTUs) of Erysipelotrichaceae (increased in patients), Allobaculum (decreased in patients), and Faecalibacterium prausnitzii (increased in patients) showed different relative abundance in Italian patient baseline samples compared to controls after controlling for multiple comparisons. Some OTUs differed between Dutch patient samples and healthy controls, but no evidence remained after controlling for multiple comparisons. No differences were found in paired analysis between Italian patient baseline and inactive disease samples. CONCLUSION: Our findings show evidence for dysbiosis in JIA patients. Only patient/control status, age, and geographic origin appear to be drivers of the microbiota profiles, regardless of disease activity stage, inflammation, and markers of autoimmunity.

Clinical signs and symptoms in a joint model of four disease activity parameters in juvenile dermatomyositis: a prospective, longitudinal, multicenter cohort study.

BACKGROUND: It is currently impossible to predict the prognosis of patients with juvenile dermatomyositis (JDM). The aim of this study was to find clinical features most strongly associated with outcome variables in JDM as a first step towards tailor-made treatment. METHODS: In a large, prospectively followed, multicenter cohort study of 340 patients with JDM, each contributing multiple visits, a Bayesian model of disease activity was developed, using the four continuous outcome variables creatine kinase (CK), childhood myositis assessment score (CMAS), manual muscle testing of 8 muscle groups (MMT8) and the physician's global assessment of disease activity (PGA). Covariates were clinical signs and symptoms. Correlations among visits of the same patient were resolved by introducing subject-specific random effects. RESULTS: Myalgia and dysphonia were associated with worse disease activity according to all outcome variables. Periorbital rash, rash on the trunk, rash over large joints, nail fold changes and facial swelling were associated with higher PGA. Notably, periorbital rash was also associated with higher CK and lower CMAS and nail fold changes with lower CMAS. Contractures were associated with lower CMAS and MMT8 and higher PGA. Patients with higher CMAS exhibited a higher MMT8 as well. PGA had the highest probability among the four outcome variables of being abnormal even if the other three outcome variables were normal. CONCLUSIONS: The signs and symptoms associated with disease activity could be used to stratify patients and adapt treatment plans to disease activity. The correlation between CMAS and MMT8 and the unique information captured by PGA implied that PGA should be maintained as an outcome variable, whereas CMAS and MMT8 might be simplified.

Effect of the Inclusion of the Metacarpophalangeal Joints on the Wrist Magnetic Resonance Imaging Scoring System in Juvenile Idiopathic Arthritis.

OBJECTIVE: To extend the magnetic resonance imaging (MRI) score for assessment of wrist synovitis in juvenile idiopathic arthritis (JIA) by inclusion of the metacarpophalangeal (MCP) joints, and to compare the metric properties of the original and the extended score. METHODS: Wrist MRI of 70 patients with JIA were scored by 3 independent readers according to (1) the wrist component of the rheumatoid arthritis MRI synovitis score (comprising distal radioulnar, radiocarpal, and combined midcarpal and carpometacarpal joints); and (2) an extended score including the MCP joints. Thirty-eight patients had a 1-year MRI followup. The concordance between the readers [intraclass correlation coefficient (ICC), 95% limits of agreement (LOA), and weighted Cohen's κ], correlations with clinical variables (Spearman's ϱ), and the sensitivity to change [standardized response mean (SRM)] were calculated for both scores. RESULTS: The interreader agreement was moderate for the original score (ICC 0.77; 95% CI 0.68-0.84) and good for the extended score (ICC 0.86; 95% CI 0.80-0.91). Using 95% LOA, the aggregate score variability was less favorable with relatively wide LOA. Weighted Cohen's κ of the individual joints indicated good agreement for the original score and good to excellent agreement for the extended score. Correlations with clinical variables reflecting disease activity improved for the extended score and its SRM was higher compared to that of the original score. CONCLUSION: The extended score showed better reliability, construct validity, and sensitivity to change than the original. Inclusion of the MCP joints should be considered for a more accurate assessment of disease activity and treatment efficacy in JIA.

Patient's experiences with the care for juvenile idiopathic arthritis across Europe.

BACKGROUND: To assess the views of juvenile idiopathic arthritis (JIA) patients and their parents on the care and treatment they receive in referral pediatric rheumatology centers throughout Europe. METHODS: In a collaboration between physicians and patient associations, a questionnaire was developed, covering various domains of JIA care, including demographics, diagnosis, referrals to various health care professionals, access to pain and fatigue management and support groups, information they received about the disease and awareness of and participation in research. The questionnaire was translated and distributed by parent associations and pediatric rheumatologists in 25 countries, 22 of which were European. After completion the replies were entered on the PRINTO website. Replies could either be entered directly by parents on the website or on paper. In these cases, the replies were scanned and emailed by local hospital staff to Utrecht where they were entered by I.R. in the database. RESULTS: The survey was completed by 622 parents in 23 countries. The majority (66.7%) of patients were female, with median age 10-11 years at the completion of the questionnaire. Frequencies of self-reported JIA categories corresponded to literature. Some patients had never been referred to the ophthalmologist (22.8%) or physiotherapist (31.7%). Low rates of referral or access to fatigue (3.5%) or pain management teams (10.0%), age appropriate disease education (11.3%), special rehabilitation (13.7%) and support groups (20.1%) were observed. Many patients indicated they did not have contact details for urgent advice (35.9%) and did not receive information about immunizations (43.2%), research (55.6%) existence of transition of care clinics (89,2%) or financial support (89.7%). While on immunosuppressive drugs, about one half of patients did not receive information about immunizations, travelling, possible infections or how to deal with chickenpox or shingles. CONCLUSIONS: Low rates of referral to health care professionals may be due to children whose illness is well managed and who do not need additional support or information. Improvements are needed, especially in the areas of supportive care and information patients receive. It is also important to improve doctor patient communication between visits. Physicians can be instrumental in the setting up of support groups and increasing patients' awareness of existing support. Suggestions are given to convey crucial pieces of information structurally and repeatedly to ensure, among other things, compliance.

Ultrasound changes in synovial abnormalities induced by treatment in juvenile idiopathic arthritis.

OBJECTIVES: To investigate the capacity of ultrasound (US) to detect improvement of synovial abnormalities induced by treatment in juvenile idiopathic arthritis (JIA). METHODS: Eighty-three joints (33 knees, 22 tibiotalar, 10 wrists, 9 elbows, 9 subtalar joints) of 33 patients with new-onset JIA were assessed by US at study entry and 6 months after a therapeutic intervention. Each joint was scored for grey-scale (GS) and power Doppler (PD) abnormalities according to a 4-point semiquantitative scale. Pre- and post-treatment US scores were compared and the sensitivity to change of GSUS and PDUS was estimated. Clinical response was assessed using the ACR paediatric (ACRp) response criteria. RESULTS: Seventeen patients (51.5%) underwent intra-articular corticosteroid injection (IACI) only, 15 (45.5%) were given IACI and systemic medications, and 1 (3.0%) was started with systemic therapy alone. Both GSUS and PDUS scores improved significantly (p<0.0001) from baseline to follow-up. US revealed strong sensitivity to change with standardised response mean for GSUS and PDUS of 2.44 and 1.23, respectively. At the follow-up visit, 13/20 (65.0%) joints with residual US abnormalities were judged in remission on clinical grounds. Six/21 (28.6%) patients who were ACRp90 responders did not display complete resolution of synovial abnormalities on US. CONCLUSIONS: US is a sensitive tool to assess therapeutic response in patients with JIA. Subclinical disease on US is common in joints with clinically-defined remission. An ACRp90 response may not be coupled with complete resolution of synovial abnormalities on US. Further studies are needed to establish the impact of US on therapeutic decision-making in JIA.

Clinical Juvenile Arthritis Disease Activity Score proves to be a useful tool in treat-to-target therapy in juvenile idiopathic arthritis.

OBJECTIVES: To assess if the Juvenile Arthritis Disease Activity Score (JADAS71) could be used to correctly identify patients with juvenile idiopathic arthritis (JIA) in need of antitumour necrosis factor therapy (anti-TNF) therapy 3 and 6 months after start of methotrexate (MTX). METHODS: Monocentric retrospective cohort study from 2011 to 2015 analysing all patients with oligoarticular JIA (OJIA) (n=39) and polyarticular course JIA (PJIA) (n=74) first starting MTX. Three and 6 months after MTX start, clinical and laboratory features and the 2011 American College of Rheumatology (ACR) JIA treatment recommendations (ACR clinical practice guideline (ACR-CPG)) were compared between groups starting and not starting anti-TNF therapy. The sensitivity and specificity of the ACR-CPG, JADAS71 and the clinical JADAS to identify non-responders after 12 months were calculated. RESULTS: Physicians escalated patients with significantly higher physician global assessment, clinical JADAS (cJADAS) and patient Visual Analogue Scale (VAS). The decision not to escalate was correct in 70%-75% as shown by MTX response. The implementation of the ACR-CPG would increase the current anti-TNF use from 12% to 65%. The use of (c)JADAS in identifying patients in need of anti-TNF therapy outperformed the ACR-CPG with a much higher sensitivity, specificity and accuracy. The cJADAS threshold for treatment escalation at month 3 and 6 was >5 and >3 for OJIA and >7 and >4 for PJIA, respectively. The performance of the cJADAS decreased when the patient VAS contribution to the total score was restricted and overall did not improve by adding the erythrocyte sedimentation rate. CONCLUSIONS: The cJADAS identifies patients in need of anti-TNF and is a user-friendly tool ready to be used for treat to target in JIA. The patient VAS is a critical item in the cJADAS for the decision to escalate to anti-TNF.

Methotrexate intolerance in oral and subcutaneous administration in patients with juvenile idiopathic arthritis: a cross-sectional, observational study.

OBJECTIVES: Methotrexate (MTX) is the cornerstone disease-modifying anti-rheumatic drug (DMARD) in juvenile idiopathic arthritis (JIA). In Dutch patients, MTX intolerance occurred frequently and was associated with subcutaneous (SC) administration. The aim of this study was to assess the prevalence of MTX intolerance and its association with the route of administration in a German cohort of JIA patients. METHODS: A cross-sectional study of JIA patients on MTX was performed. Primary outcome was MTX intolerance, which was determined using the validated Methotrexate Intolerance Severity Score (MISS) questionnaire. The prevalence of gastrointestinal adverse effects and MTX intolerance was compared between patients on MTX SC and MTX administered orally (PO). RESULTS: Of 179 JIA patients on MTX, 73 (40.8%) were intolerant. The odds of MTX intolerance were higher in patients using MTX exclusively SC compared to exclusively PO (adjusted odds ratio 3.37 [95% confidence interval 1.19-10.0]). There was strong evidence that the former experienced more behavioural complaints (76.1% vs. 47.4%, p=0.001) and weak evidence that they experienced more abdominal pain after MTX intake (43.5% vs. 27.4%, p=0.056). CONCLUSIONS: The prevalence of MTX intolerance was high and exclusively SC administration of MTX was associated with MTX intolerance and behavioural adverse effects. The prevalence of gastrointestinal adverse effects was at least as high as in patients on MTX PO. The frequently held assumption that SC causes fewer side effects than PO seems unwarranted. Definite answers about the differences between SC and PO administration with respect to safety and efficacy should be obtained by randomised trials.

A Patient-Specific Foot Model for the Estimate of Ankle Joint Forces in Patients with Juvenile Idiopathic Arthritis.

Juvenile idiopathic arthritis (JIA) is the leading cause of childhood disability from a musculoskeletal disorder. It generally affects large joints such as the knee and the ankle, often causing structural damage. Different factors contribute to the damage onset, including altered joint loading and other mechanical factors, associated with pain and inflammation. The prediction of patients' joint loading can hence be a valuable tool in understanding the disease mechanisms involved in structural damage progression. A number of lower-limb musculoskeletal models have been proposed to analyse the hip and knee joints, but juvenile models of the foot are still lacking. This paper presents a modelling pipeline that allows the creation of juvenile patient-specific models starting from lower limb kinematics and foot and ankle MRI data. This pipeline has been applied to data from three children with JIA and the importance of patient-specific parameters and modelling assumptions has been tested in a sensitivity analysis focused on the variation of the joint reaction forces. This analysis highlighted the criticality of patient-specific definition of the ankle joint axes and location of the Achilles tendon insertions. Patient-specific detection of the Tibialis Anterior, Tibialis Posterior, and Peroneus Longus origins and insertions were also shown to be important.

Early predictors of prognosis in juvenile idiopathic arthritis: a systematic literature review.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is subdivided into seven categories. Even within these categories, the prognosis varies markedly. To start appropriate treatment in patients with JIA and to inform patients and their parents correctly, it is essential to know the individual prognosis, preferably at the time of diagnosis. The aim of this study was to identify variables that predict disease activity, joint damage, functional ability and quality of life (QoL) early in the disease course. METHODS: A systematic literature review was performed, and 3679 articles were identified. The results were screened and critically appraised using predefined criteria. Articles that described validated outcomes, such as the Wallace criteria, the childhood health assessment questionnaire (CHAQ) and the juvenile arthritis damage index (JADI), and that determined predictors in the first 6 months of disease were selected. RESULTS: Forty mostly retrospective articles were selected. Polyarticular onset predicted a worse prognosis for all outcomes, except QoL. A diagnostic delay and the systemic category predicted continuation of active disease. Notably, antinuclear antibodies (ANA) did not predict disease activity. Symmetric involvement and rheumatoid factor positivity predicted less damage. More disease activity was mainly associated with worse functional outcome. However, most predictors were not validated. CONCLUSIONS: Few predictors for the selected outcomes were found. Prospective, longitudinal studies using standardised outcome measurements, and evaluating a broader range of predictors, such as genetics, immunological and imaging data, should be performed. For the outcomes joint assessment and quality of life, standardised and validated outcomes should be developed.

Prediction of methotrexate efficacy and adverse events in patients with juvenile idiopathic arthritis: a systematic literature review.

BACKGROUND: Methotrexate (MTX) is the cornerstone disease-modifying anti-rheumatic drug in juvenile idiopathic arthritis (JIA). In JIA, it is important to start effective treatment early to avoid long-term sequelae, such as joint damage. To accomplish this goal, it is crucial to know beforehand who is going to respond well to MTX. In addition, MTX adverse effects such as MTX intolerance occur frequently, potentially hindering its efficacy. To avoid inefficacy of an otherwise effective drug, the physician should be timely aware of these adverse events. Consequently, to optimise treatment of JIA patients with MTX, predictors for efficacy and adverse events should be used in daily clinical practice. The aim of this study was to summarise the existing knowledge about such predictors. METHODS: A systematic literature search was performed in PubMed, Embase and The Cochrane Library, and 1,331 articles were identified. These were selected based on their relevance to the topic and critically appraised according to pre-defined criteria. Predictors for MTX efficacy and adverse events were extracted from the literature and tabulated. RESULTS: Twenty articles were selected. The overall quality of the studies was good. For MTX efficacy, candidate predictors were antinuclear antibody positivity, the childhood health assessment questionnaire score, the myeloid-related protein 8/14 level, long-chain MTX polyglutamates, bilateral wrist involvement and some single nucleotide polymorphisms (SNPs) in the adenosine triphosphate binding cassette and solute carrier transporter gene families. For MTX adverse events, potential predictors were alanine aminotransferase and thrombocyte level and two SNPs in the γ-glutamyl hydrolase and methylenetetrahydrofolate reductase genes. However, validation of most predictors in independent cohorts was still lacking. CONCLUSIONS: Interesting candidate predictors were found, especially for MTX efficacy. However, most of these were not validated. This should be the goal of future efforts. A clinically relevant way to validate the predictors is by means of creating a clinical prediction model.

Prediction of clinical non-response to methotrexate treatment in juvenile idiopathic arthritis.

OBJECTIVES: Methotrexate (MTX) is a cheap and efficacious drug in juvenile idiopathic arthritis (JIA) treatment. If JIA patients are unresponsive to MTX, early and effective combination treatment with biologicals is required to prevent joint damage. The authors developed a prediction model to identify JIA patients not responding to MTX. METHODS: In a cohort of 183 JIA patients, clinical variables and single nucleotide polymorphisms (SNPs) in genes involved in the mechanism of action of MTX were determined at the start of MTX treatment. These variables were used to construct a prediction model for non-response to MTX treatment during the first year of treatment. Non-response to MTX was defined according the American College of Rheumatology paediatric 70 criteria. The prediction model was validated in a cohort of 104 JIA patients. RESULTS: The prediction model included: erythrocyte sedimentation rate and SNPs in genes coding for methionine synthase reductase, multidrug resistance 1 (MDR-1/ABCB1), multidrug resistance protein 1 (MRP-1/ABCC1) and proton-coupled folate transporter (PCFT). The area under the receiver operating characteristics curve (AUC) was 0.72 (95% CI: 0.63 to 0.81). In the validation cohort, the AUC was 0.65 (95% CI: 0.54 to 0.77). The prediction model was transformed into a total risk score (range 0-11). At a cut-off of ≥3, sensitivity was 78%, specificity 49%, positive predictive value was 83% and negative predictive value 41%. CONCLUSIONS: The prediction model that we developed and validated combines clinical and genetic variables to identify JIA patients not responding to MTX treatment. This model could assist clinicians in making individualised treatment decisions.

[Bad aftertaste caused by pine nuts]. / Een vieze smaak in de mond door pijnboompitten.

BACKGROUND: Dysgeusia caused by the consumption of pine nuts is not widely reported in the medical literature, although much is written about this condition on the Internet. CASE DESCRIPTION: We present the case of a 46-year-old male who complained of metallic and bitter dysgeusia that started 2 days after the ingestion of approximately 70 grams of pine nuts. A literature search revealed only 3 case reports on this subject. In all cases including ours, the complaints began a few days after the ingestion of pine nuts and had spontaneously resolved after a week. No medical sequelae are known, but patients may suffer social consequences. CONCLUSION: The cause of this condition is unknown. Possible causes include the presence of toxic or inedible components in the pine nuts. Physicians should be aware of this phenomenon in order to be able to reassure patients about this benign disorder.

High prevalence of methotrexate intolerance in juvenile idiopathic arthritis: development and validation of a methotrexate intolerance severity score.

OBJECTIVE: To design and validate a new questionnaire for identifying patients with methotrexate (MTX) intolerance, and to determine the prevalence of MTX intolerance in patients with juvenile idiopathic arthritis (JIA) using this questionnaire. METHODS: The MTX Intolerance Severity Score (MISS) questionnaire was constructed, consisting of 5 domains: stomach ache, nausea, vomiting, sore mouth, and behavioral symptoms. The domains each consisted of 3 questions pertaining to the presence of a symptom upon, prior to (anticipatory), and when thinking of (associative) MTX intake. The MISS questionnaire was validated in 86 patients by determining its discriminative power between patients with and those without MTX intolerance, identified as such by a gold standard (physician's opinion). Using the MISS questionnaire, the prevalence of MTX intolerance was determined in 297 JIA patients. RESULTS: The MISS questionnaire discriminated well between MTX-intolerant and MTX-tolerant patients. A cutoff score of 6 yielded the best sensitivity (88%) and specificity (80%). MTX intolerance was found in 150 (50.5%) of 297 patients. Of 220 patients receiving oral MTX, 98 (44.5%) experienced MTX intolerance, whereas 67.5% of 77 patients receiving parenteral MTX experienced intolerance to the drug (P = 0.001). CONCLUSION: Our findings indicate that the MISS questionnaire is a highly sensitive and specific tool for the diagnosis of MTX intolerance, and that there is a high prevalence of MTX intolerance among JIA patients. The prevalence of intolerance in patients receiving parenteral MTX exceeds that in patients receiving oral MTX. The frequent occurrence of anticipatory and associative symptoms suggests that classic conditioning plays an important role in MTX intolerance.